an aquatic shellfish (generally limited to mollusks with calcareous shells such as clams or snails, and excluding crustaceans such as shrimp or crabs)

shell, crust, chaff / husk, hull

(chemistry) inner shell (a set of atomic orbitals with a relatively low principal quantum number)

inside, within (physical location) / between, among / while, during, inside or within a span of time / (when used possessively) one's own, my, our

sooner or later / eventually / before long

observe

observation

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend